Light sensitive copying compositions containing a light insensitive polymer and a light sensitive heterocyclic composition are known. For example, U.S. Pat. No. 3,776,735 discloses a light sensitive copying composition comprising a high molecular weight light-insensitive polymer containing units having carboxylic groups, phosphonic acid groups, sulfonic acid groups or N-arylsulfonyl urethane groups together with certain light sensitive nitrogen compounds containing at least one six-membered N-heterocyclic nucleus and at least one benzene nucleus. Forming the composition into a film, exposing the film to light in an imagewise manner with subsequent development of the exposed film provides a visible image.
Preparation of relief images by the photoinduced degradation of poly(formaldehyde) is disclosed in U.S. Pat. No. 2,892,712 (Example VII). In this method, a thin film of formaldehyde polymer coated with a thin layer of omega, omega-dibromoacetophenone is irradiated with ultraviolet light and baked at 105.degree.C. to provide a sheet having a letter text incised into the surface of the film.
It is an object of the present invention to provide a novel imaging method based upon the photodegradation of certain degradable polymers.
It is a further object to provide such a method in which sharp, distinct images having high resolution are obtained.
An additional object is to provide such a method in which no separate development step is required after exposure.